Rearrange the 2nd equation to make x the subject
so it would be x = 11-2y
so now the 1st equation would be 3(11-2y)+6y
Expand so its 33-6y+6y
So its just 33
Knowing that y is now 33
We use that into either equations, so x+2y=11
Would be x+66=11
So x is -55
